It pumps blood. Duh. Well, for most of history, people were unsure what the heart's main function was. Even Leonardo Da Vinci gave up studying it and he's probably one of the five smartest guys ever. Even now, it's not as easy as it should be to find out how the ticker works. Don't worry, this Ted-Ed animation will… »5/21/14 9:36pm 5/21/14 9:36pm

The world is one step closer to a future where tiny ship-like vessels travel through our veins and fix our health problems. Recently, doctors across the United States implantedthe world's smallest pacemaker into cardiac patients. The device is roughly the size of a large vitamin and is attached directly to the heart… »5/05/14 2:06pm 5/05/14 2:06pm

This amazing 3D piece of silicone dotted with electronics looks like something out of the future—because it is. In fact, this potential pacemaker replacement fits over the human heart and is capable of monitoring and, soon, responding to, its vital signs. »3/25/14 10:00pm 3/25/14 10:00pm

You're looking at a rabbit's heart beating outside the animal that once hosted it. It's alive, pumping blood on its own thanks to a revolutionary electronic membrane that may save your life by keeping your heart beating at a perfect rate. »3/02/14 2:37pm 3/02/14 2:37pm

Buh-bum. Buh-bum. Buh-bum. We all have our own interpretations of what a heartbeat sounds like but here is what it looks like during heart surgery. It looks like it's rolling in place inside your chest. Pretty amazing. »2/21/14 8:57pm 2/21/14 8:57pm

Say what you will about these sperm-like bio-bots; they've got heart. The beating of live heart cells propels a tail back and forth, so that these self-powered swimming bio-bots—the first of their kind—could one day wriggle through your body delivering drugs. No batteries needed. »1/22/14 6:20pm 1/22/14 6:20pm

It may surprise you that, despite our seemingly vast knowledge of the human body, we're still decently in the dark when it comes to the smaller portions of the cardiovascular system. Even more surprising, the answer to that problem isn't lying in more powerful microscopes. It's in a heart pumping pure, shiny liquid… »12/06/13 4:40pm 12/06/13 4:40pm

The question of how long someone's heart would have to be stopped for before you can safely say that regardless of what you do, you're not going to be able to revive them is avery tricky question. It's not as simple as saying after 10 or even 20 minutes there's no hope. For instance, there are countless people who… »11/04/13 6:20am 11/04/13 6:20am

Though this sounds like a joke, former Vice President Don Cheney and his doctors were legitimately scared about him getting assassinated via terrorists hacking into his defibrillator and causing a heart attack. So they turned off the wireless feature so nobody would kill him via heart hack. »10/18/13 10:57pm 10/18/13 10:57pm

Every year the UK's British Heart Foundation runs a competition to find the most interesting images produced by its researchers—and 2013 is a good, good year. Here are some of our favorites. »7/25/13 7:01pm 7/25/13 7:01pm

The idea of putting a decaying radioactive isotope inside your chest might make you a little uneasy—and rightly so. But in 1967, the National Heart Institute and the Atomic Energy Agency set out to make it happen in the form of a plutonium-238-powered atomic heart. Think Tony Stark with nuclear waste in his chest. »3/22/13 2:00pm 3/22/13 2:00pm

Have you ever wondered how many heartbeats an average person has in their lifetime? What about for cats or dogs or other animals? Turns out because of metabolic rates and size of different species, each animal gets around a billion beats. »2/08/13 11:00pm 2/08/13 11:00pm

Discover Magazine has an amazing story about how a woman needed to be carried upside down in order to stay alive. It sounds crazy but it's real. The reason she had to be held upside down was because her pacemaker had become disconnected from her heart and holding her upside down led the pacemaker to be reconnected. »9/02/12 1:00pm 9/02/12 1:00pm

Calcium supplements—previously thought to help prevent heart disease and stroke—have now been shown to almost double the risk of heart attack. Doctors are now warning that such supplements should be taken with caution, and even then only for vital medical reasons. »5/24/12 6:26am 5/24/12 6:26am